928 engine cooling fan not activating

[sprocket]

Hello Porsche fans,

I have just purchased my first 928 and she is a beauty. It's only been a few weeks. Now I'm doing what I love the most which is tinker and make it even more perfect. On a recent cruise, I noticed that the engine temp got really hot (after being idle for a minute or two). I was just around the corner so I went home immediately. The red light litt up as I pulled in the garage. I parked it immediately and turn her off. the previous owner mentioned that the fan should run even after you turn the car off and remove the key but no such thing happen. I also notice that coolant started dripping on the floor. I determined that it was just coming from the reservoir from the overheating.

with that, I was confused because the fan didn't kick in. I took the car out again today and she seems to stay cool when running at speed (35mph or more). but once again would heat up when stopped at lights or driving at slow speeds. I could not hear the fan kick in at all. But I noticed something strange, the fan inside the car cabin would kick in on bust for about 10 secs randomly. At any point it would just blow at top speed even with the control knob turned off! what's up with that?

this is my first 928 and I'm looking for some direction. I should also mention that the fan was changed to an electric one. Hopefully that doesn't complicate things too much.

Any help is appreciated.

Roch.

[sprocket]

I checked the fuses today and they were good. I pulled the relay (XVIII) and shorted 30 and 87 with ignition turned on. Nothing happened. Does that mean a fuse is gone or something along the that line? Or does that mean faulty relay.The car also has another relay under the hood which seems to be added when they put the aftermarket fan in. When I short that one, the fan kicks in. So the big question is, should the relay on the fuse panel when shorted activate the fan just like when I short the relay under the hood?

[sprocket]

What's happening? Heard a pop sound while car was idling in driveway and steam starts pouring out of right front of car. You could tell something was releasing pressure. I shut her off right away. The strange part was that the car was not in the danger zone in terms of temperature. But I did notice that the AC was blowing hot air today which I thought was strange, especially since it was ice cold yesterday. So after inspecting the general area of where the steam came from, I'm concluding that it may have something to do with the AC compressor. Can someone offer an opinion on that? There was a very minor trace of a leak on the surface of the belly pan. No big gusher. Can the AC compressor make a pop sound and spring a leak? It scared the bejesus out of me. I thought I blew the engine or something. Any help is appreciated....

Roch.

[JFP in PA]

What's happening? Heard a pop sound while car was idling in driveway and steam starts pouring out of right front of car. You could tell something was releasing pressure. I shut her off right away. The strange part was that the car was not in the danger zone in terms of temperature. But I did notice that the AC was blowing hot air today which I thought was strange, especially since it was ice cold yesterday. So after inspecting the general area of where the steam came from, I'm concluding that it may have something to do with the AC compressor. Can someone offer an opinion on that? There was a very minor trace of a leak on the surface of the belly pan. No big gusher. Can the AC compressor make a pop sound and spring a leak? It scared the bejesus out of me. I thought I blew the engine or something. Any help is appreciated....Roch.

Yes, a failing AC line or component can make a fairly loud sound when it vents off the gas. Have the AC system tested for operating pressures, bet you find yours is zero..........

[sprocket]

So I should be able to operate the car still with AC turned off? Thanks for the insight.

Anyone else out there that can offer ideas on my initial problem of engine overheating/cooling fan issues?

Thanks

[stepson]

Since your fan is aftermarket, my bet would be that the aftermarket relay under the hood has gone bad. Replace the relay.

[drymartiniwi]

I also think it's the aftermarket relay that's bad. By pass it to test if fan runs. If it does then the relay is bad.

[GSpence2]

what year 928?